Woven wire belt for paper making machines



July 27, 1937. H. G. SPECHT WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed March 25, 1936 2 Sheets-Sheet? 1 E 5 gig? i A zry Fg fiy 2. .23

' INVENTOR HHR'RY 6r. j smr ATTORNEY July 27, 1937. H. cs. SPECHT 2,033,449

WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed March 25, 1936 2 Sheets-Sheet 2 INVENTOK. HQRRY G". 5 EcHT A TTORN Patented July 27, 1937 WOVEN WIRE BELT FOR PAPER MAKING MACHINES Harry G. Specht, Montclair, N. J., assignor, by

mesne assignments,

to Encor Corporation,

Belleville, N. 'J., a corporation of New Jersey Application March 23, 1396, Serial No. 70,529

1 Claim.

The present invention relates to woven wire belts particularly for paper making machines of the Fourdrinier type, and is an improvement over the woven wire belts disclosed in my U. S. Letters Patent Nos. 2,003,123 and 2,003,124 granted May 28, 1935. These belts, as is well known, are in the form of a continuous band of fine wire mesh which moves over spaced supporting rolls and in contact with suction boxes and rolls. According to the invention disclosed in said patents greater strength and flexibility, as well as improved drainage characteristics and better paper formation surface, were obtained by providing the warp wires in the form of fiat ribbon like wires which were interwoven with shoot or weft wires of circular cross-section, the knuckles of the weft wires being formed about the flattened surfaces of the warp wires. Also according to these inventions, a much finer beat up of the woven wire was permitted, with an increase in the flat knuckle surfaces of the warp wires whereby a greatly increased wearing surface was produced.

It is proposed in the present invention to provide shoot or weft wires which will permit of a flatter type of weave, that is, a decreased thick-, ness dimension without sacrifice of strength, and in which the weft knuckles will be permitted to come closer to or in line with the warp knuckles at the paper formation side, so that the wire will have a better paper formation surface producing less wire mark in the paper. To this end it is proposed to provide shoot or weft wires in the form of twisted wire, which due to the twisted strands from which the wire is formed will be slightly crushed at the knuckles while maintaining its normal cross-section between the knuckles.

The invention has application in both regular weave wires, and in twill weave wires in which the warp wires are carried under two and over one weft wire to provide longer knuckles and greater wearing surface at the under side. In the case of twillweave the relatively large paper formation and wear surfaces of the warp and weft wires will make for a much finer paper formation surface, as distinguished from the usual type of twill weave in which the paper formation surface had long deep depressions due to the spacing of the warp knuckles to every third weft wire instead of to every second weft wire as in the regular weave. By increasing the length of the weft knuckles, and at the same time obtaining a finer beat up due to the ribbon like warp wires, the depresslons'are not only decreased in size, but the walls ofthe mesh openings have less convergence and therefore will provide better support for the paper fibres with less tendency for the fibres to turn down into" the mesh openmgs. g

According to my invention there will be an increase in the weft knuckle surfaces both in the direction of the weft and in the direction of the warp wires, the increase. in the direction of the weft wires being due to the formation of the. weft knuckles over the flat warp wires, and the increase in the directionrof warp'being due to the slight crushing of *the'twisted cable weft wires in the direction of the warp, as distinguished fromthe solid wire-circular cross-section weft wires heretofore employed.

With the above and other objects in view embodiments of the invention are shown in the accompanying drawings, and these embodiments will be hereinafter :more fully described with reference thereto, and the invention will be finally pointed out in the claim.

In the drawings:

Fig. l is an enlarged plan view of a portion of 'a regular weave wire belt, according to one illustrated exemplary embodiment of my invention.

Fig. 2 is a longitudinalsectional view, taken-- along the line 2--2 of Fig. l. I

Fig. 3 is a transverse sectional view, taken along the line 33 of Fig. 1. r

Fig. 4 is an enlarged plan view of a portion of a twill weave wire belt, according to another illustrated exemplary embodiment of my inven-,

tion.

Fig. 5 is a longitudinal sectional view taken along the line 55 of Fig. 4.

Fig. 6 is a transverse sectional view, taken along the line 6-6 of Fig. 4.

Similar reference characters indicate corresponding parts throughout the several figures of the drawings.

Referring to Figs. 1 to 3 of the drawings, the Fourdrinier wire, according to the exemplary embodiment shown therein, comprises warp wires 10 of flat ribbon-like form, and twisted cable weft wires ll preferably formed of three, four or five twisted threads of fine wire and replacing the usual solid circular cross-section weft wires. The. upwardly crimped knuckles of both the warp and weft wires provide the upper paper formation surface, and the downwardly bent knuckles provide the lower wearing surface. In the proper weaving of the wire the warp should control or predominate the weft. The solid warp wires woven with the highly flexible and compressible twisted cable weft wires permit of beating the weft wires up to a finer mesh, the fiattened warp wires being highly flexible and directly taking the punishment and strain necessary in this operation. The weft wires, which are shaped by and follow the action of the warp wires, only indirectly take the strain imposed by the beating up operation, and should not be such as to overcome the predominance or control of the warp wires. Where both the warp and weft are solid and of the same material, this control is lost to a certain extent, depending on the alloysused, as neither the warp nor the weft will predominate over the other. The use of twisted cable weft wire permits this control of the warp wires to be maintained irrespective of the material. Other material than bronze and brass may be used for the warp and weft, as for instance stainless steel.

The dimensions of the warp wires are proportioned with respect to the weft wire diameter, the width being such as to provide a relatively wide paper formation and wear surface and the thickness being such as to permit a fine beat up of the weft, and at the same time allow the knuckles of the weft, with, a lesser deformation in the crimping of the weft than in the warp and with a slight crushing at the knuckles to come into or very close to the. plane of the warp knuckles; For instance with .009 of an inch thickness weft wires the width of the warp wires may be .012 of an inch and the thickness .004 of an inch. The relative thinness of the fiat warp wires, it will be seen, allows beating up a large number of weft wires per inch, whiletheir relative widenes gives an area equivalent to or greater than that of the largest round warp wire permissible. The edges of the warp wires are preferably slightly rounded to allow free drainage through the mesh openings.

The knuckles of the weft-wires are increased in the weft direction by being formed over the flat warp wires and are increased in the warp direction by being slightly crushed in the weaving. The two directional flat knuckles of the weft produce a paper formation surface in which the fibres will be supported by fiat contact, as

distinguished from the point contact with wires having circular cross-section warp and weft wires. At the same time the fine beat up of the weft provides a smooth surface which will support the paper stock without the usual tendency to turn down intov the mest and clog it. Without sacrificing this support the mesh openings may be of adequate size to provide full drainage. The grooving in the twisted cable weft wires also makes for better drainage.

The fiat warp wires while providing, a much greater tensile strength are at the same time more flexible than circular cross-section warp wires, so that they may be operated at high speed over rolls for a considerably greater time than heretofore beforefatigue sets in.

In the modification shown in Figs. 4 to 6 the Fourdrinier wire is a twill weave, the warp wires it being wovenunder two pairs and over one pair of the twisted cable weft wires ll, thus providing very long knuckles on the wear side.

I have illustrated and described a preferred and satisfactory embodiment of my invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof, as defined in the appended claim.

Having thus described my invention what I claim and desire to secure by Letters Patent is:-

Woven wire fabric for paper making machines comprising interwoven fine gauge warp and fine gauge twisted cable weft wires with knuckles produced in both the warp and weft wires, the

warp wires throughout their length being of uniform non-circular cross-section elongated in one dimension, said elongated dimension being parallel to the plane of the woven wire fabric whereby the weft knuckles cross the elongated faces of the warp wires and have their outer projected surfaces substantially co-extensive transversely with said elongated faces, said outer projected surfaces being slightly flattened by crushing of said weft wires at their points of engagement with the warp knuckles to produce substantially flattened paper stock supporting surface areas having flatness in both the length and breadth of the wire.

. HARRY G. SPECHT. 

